/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.bangcommunity.bbframe.common.utils.reflect;

import com.bangcommunity.bbframe.common.utils.lang.ArrayUtils;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

/**
 * <p>
 * Utility reflection methods focused on {@link Method}s, originally from Commons BeanUtils.
 * Differences from the BeanUtils version may be noted, especially where similar functionality
 * already existed within Lang.
 * </p>
 *
 * <h3>Known Limitations</h3>
 * <h4>Accessing Public Methods In A Default Access Superclass</h4>
 * <p>
 * There is an issue when invoking {@code public} methods contained in a default access superclass
 * on JREs prior to 1.4. Reflection locates these methods fine and correctly assigns them as
 * {@code public}. However, an {@link IllegalAccessException} is thrown if the method is invoked.
 * </p>
 *
 * <p>
 * {@link MethodUtils} contains a workaround for this situation. It will attempt to call
 * {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} on this method. If this call
 * succeeds, then the method can be invoked as normal. This call will only succeed when the
 * application has sufficient security privileges. If this call fails then the method may fail.
 * </p>
 *
 * @since 2.5
 * @version $Id: MethodUtils.java 1583482 2014-03-31 22:54:57Z niallp $
 */
public class MethodUtils {

    /**
     * <p>
     * {@link MethodUtils} instances should NOT be constructed in standard programming. Instead, the
     * class should be used as {@code MethodUtils.getAccessibleMethod(method)}.
     * </p>
     *
     * <p>
     * This constructor is {@code public} to permit tools that require a JavaBean instance to
     * operate.
     * </p>
     */
    public MethodUtils() {
        super();
    }

    /**
     * <p>
     * Invokes a named method whose parameter type matches the object type.
     * </p>
     *
     * <p>
     * This method delegates the method search to
     * {@link #getMatchingAccessibleMethod(Class, String, Class[])}.
     * </p>
     *
     * <p>
     * This method supports calls to methods taking primitive parameters via passing in wrapping
     * classes. So, for example, a {@code Boolean} object would match a {@code boolean} primitive.
     * </p>
     *
     * <p>
     * This is a convenient wrapper for
     * {@link #invokeMethod(Object object,String methodName, Object[] args, Class[] parameterTypes)}.
     * </p>
     *
     * @param object
     *            invoke method on this object
     * @param methodName
     *            get method with this name
     * @param args
     *            use these arguments - treat null as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException
     *             if there is no such accessible method
     * @throws InvocationTargetException
     *             wraps an exception thrown by the method invoked
     * @throws IllegalAccessException
     *             if the requested method is not accessible via reflection
     */
    public static Object invokeMethod(final Object object, final String methodName, Object... args)
            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
        args = ArrayUtils.nullToEmpty(args);
        final Class<?>[] parameterTypes = ClassUtils.toClass(args);
        return invokeMethod(object, methodName, args, parameterTypes);
    }

    /**
     * <p>
     * Invokes a named method whose parameter type matches the object type.
     * </p>
     *
     * <p>
     * This method delegates the method search to
     * {@link #getMatchingAccessibleMethod(Class, String, Class[])}.
     * </p>
     *
     * <p>
     * This method supports calls to methods taking primitive parameters via passing in wrapping
     * classes. So, for example, a {@code Boolean} object would match a {@code boolean} primitive.
     * </p>
     *
     * @param object
     *            invoke method on this object
     * @param methodName
     *            get method with this name
     * @param args
     *            use these arguments - treat null as empty array
     * @param parameterTypes
     *            match these parameters - treat null as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException
     *             if there is no such accessible method
     * @throws InvocationTargetException
     *             wraps an exception thrown by the method invoked
     * @throws IllegalAccessException
     *             if the requested method is not accessible via reflection
     */
    public static Object invokeMethod(final Object object, final String methodName, Object[] args,
            Class<?>[] parameterTypes) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
        parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
        args = ArrayUtils.nullToEmpty(args);
        final Method method = getMatchingAccessibleMethod(object.getClass(), methodName, parameterTypes);
        if (method == null) {
            throw new NoSuchMethodException(
                    "No such accessible method: " + methodName + "() on object: " + object.getClass().getName());
        }
        return method.invoke(object, args);
    }

    /**
     * <p>
     * Invokes a method whose parameter types match exactly the object types.
     * </p>
     *
     * <p>
     * This uses reflection to invoke the method obtained from a call to
     * {@link #getAccessibleMethod}(Class,String,Class[])}.
     * </p>
     *
     * @param object
     *            invoke method on this object
     * @param methodName
     *            get method with this name
     * @param args
     *            use these arguments - treat {@code null} as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException
     *             if there is no such accessible method
     * @throws InvocationTargetException
     *             wraps an exception thrown by the method invoked
     * @throws IllegalAccessException
     *             if the requested method is not accessible via reflection
     */
    public static Object invokeExactMethod(final Object object, final String methodName, Object... args)
            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
        args = ArrayUtils.nullToEmpty(args);
        final Class<?>[] parameterTypes = ClassUtils.toClass(args);
        return invokeExactMethod(object, methodName, args, parameterTypes);
    }

    /**
     * <p>
     * Invokes a method whose parameter types match exactly the parameter types given.
     * </p>
     *
     * <p>
     * This uses reflection to invoke the method obtained from a call to
     * {@link #getAccessibleMethod(Class,String,Class[])}.
     * </p>
     *
     * @param object
     *            invoke method on this object
     * @param methodName
     *            get method with this name
     * @param args
     *            use these arguments - treat null as empty array
     * @param parameterTypes
     *            match these parameters - treat {@code null} as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException
     *             if there is no such accessible method
     * @throws InvocationTargetException
     *             wraps an exception thrown by the method invoked
     * @throws IllegalAccessException
     *             if the requested method is not accessible via reflection
     */
    public static Object invokeExactMethod(final Object object, final String methodName, Object[] args,
            Class<?>[] parameterTypes) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
        args = ArrayUtils.nullToEmpty(args);
        parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
        final Method method = getAccessibleMethod(object.getClass(), methodName, parameterTypes);
        if (method == null) {
            throw new NoSuchMethodException(
                    "No such accessible method: " + methodName + "() on object: " + object.getClass().getName());
        }
        return method.invoke(object, args);
    }

    /**
     * <p>
     * Invokes a {@code static} method whose parameter types match exactly the parameter types
     * given.
     * </p>
     *
     * <p>
     * This uses reflection to invoke the method obtained from a call to
     * {@link #getAccessibleMethod(Class, String, Class[])}.
     * </p>
     *
     * @param cls
     *            invoke static method on this class
     * @param methodName
     *            get method with this name
     * @param args
     *            use these arguments - treat {@code null} as empty array
     * @param parameterTypes
     *            match these parameters - treat {@code null} as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException
     *             if there is no such accessible method
     * @throws InvocationTargetException
     *             wraps an exception thrown by the method invoked
     * @throws IllegalAccessException
     *             if the requested method is not accessible via reflection
     */
    public static Object invokeExactStaticMethod(final Class<?> cls, final String methodName, Object[] args,
            Class<?>[] parameterTypes) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
        args = ArrayUtils.nullToEmpty(args);
        parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
        final Method method = getAccessibleMethod(cls, methodName, parameterTypes);
        if (method == null) {
            throw new NoSuchMethodException(
                    "No such accessible method: " + methodName + "() on class: " + cls.getName());
        }
        return method.invoke(null, args);
    }

    /**
     * <p>
     * Invokes a named {@code static} method whose parameter type matches the object type.
     * </p>
     *
     * <p>
     * This method delegates the method search to
     * {@link #getMatchingAccessibleMethod(Class, String, Class[])}.
     * </p>
     *
     * <p>
     * This method supports calls to methods taking primitive parameters via passing in wrapping
     * classes. So, for example, a {@code Boolean} class would match a {@code boolean} primitive.
     * </p>
     *
     * <p>
     * This is a convenient wrapper for
     * {@link #invokeStaticMethod(Class, String, Object[], Class[])}.
     * </p>
     *
     * @param cls
     *            invoke static method on this class
     * @param methodName
     *            get method with this name
     * @param args
     *            use these arguments - treat {@code null} as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException
     *             if there is no such accessible method
     * @throws InvocationTargetException
     *             wraps an exception thrown by the method invoked
     * @throws IllegalAccessException
     *             if the requested method is not accessible via reflection
     */
    public static Object invokeStaticMethod(final Class<?> cls, final String methodName, Object... args)
            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
        args = ArrayUtils.nullToEmpty(args);
        final Class<?>[] parameterTypes = ClassUtils.toClass(args);
        return invokeStaticMethod(cls, methodName, args, parameterTypes);
    }

    /**
     * <p>
     * Invokes a named {@code static} method whose parameter type matches the object type.
     * </p>
     *
     * <p>
     * This method delegates the method search to
     * {@link #getMatchingAccessibleMethod(Class, String, Class[])}.
     * </p>
     *
     * <p>
     * This method supports calls to methods taking primitive parameters via passing in wrapping
     * classes. So, for example, a {@code Boolean} class would match a {@code boolean} primitive.
     * </p>
     *
     *
     * @param cls
     *            invoke static method on this class
     * @param methodName
     *            get method with this name
     * @param args
     *            use these arguments - treat {@code null} as empty array
     * @param parameterTypes
     *            match these parameters - treat {@code null} as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException
     *             if there is no such accessible method
     * @throws InvocationTargetException
     *             wraps an exception thrown by the method invoked
     * @throws IllegalAccessException
     *             if the requested method is not accessible via reflection
     */
    public static Object invokeStaticMethod(final Class<?> cls, final String methodName, Object[] args,
            Class<?>[] parameterTypes) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
        args = ArrayUtils.nullToEmpty(args);
        parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
        final Method method = getMatchingAccessibleMethod(cls, methodName, parameterTypes);
        if (method == null) {
            throw new NoSuchMethodException(
                    "No such accessible method: " + methodName + "() on class: " + cls.getName());
        }
        return method.invoke(null, args);
    }

    /**
     * <p>
     * Invokes a {@code static} method whose parameter types match exactly the object types.
     * </p>
     *
     * <p>
     * This uses reflection to invoke the method obtained from a call to
     * {@link #getAccessibleMethod(Class, String, Class[])}.
     * </p>
     *
     * @param cls
     *            invoke static method on this class
     * @param methodName
     *            get method with this name
     * @param args
     *            use these arguments - treat {@code null} as empty array
     * @return The value returned by the invoked method
     *
     * @throws NoSuchMethodException
     *             if there is no such accessible method
     * @throws InvocationTargetException
     *             wraps an exception thrown by the method invoked
     * @throws IllegalAccessException
     *             if the requested method is not accessible via reflection
     */
    public static Object invokeExactStaticMethod(final Class<?> cls, final String methodName, Object... args)
            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
        args = ArrayUtils.nullToEmpty(args);
        final Class<?>[] parameterTypes = ClassUtils.toClass(args);
        return invokeExactStaticMethod(cls, methodName, args, parameterTypes);
    }

    /**
     * <p>
     * Returns an accessible method (that is, one that can be invoked via reflection) with given
     * name and parameters. If no such method can be found, return {@code null}. This is just a
     * convenience wrapper for {@link #getAccessibleMethod(Method)}.
     * </p>
     *
     * @param cls
     *            get method from this class
     * @param methodName
     *            get method with this name
     * @param parameterTypes
     *            with these parameters types
     * @return The accessible method
     */
    public static Method getAccessibleMethod(final Class<?> cls, final String methodName,
            final Class<?>... parameterTypes) {
        try {
            return getAccessibleMethod(cls.getMethod(methodName, parameterTypes));
        } catch (final NoSuchMethodException e) {
            return null;
        }
    }

    /**
     * <p>
     * Returns an accessible method (that is, one that can be invoked via reflection) that
     * implements the specified Method. If no such method can be found, return {@code null}.
     * </p>
     *
     * @param method
     *            The method that we wish to call
     * @return The accessible method
     */
    public static Method getAccessibleMethod(Method method) {
        if (!MemberUtils.isAccessible(method)) {
            return null;
        }
        // If the declaring class is public, we are done
        final Class<?> cls = method.getDeclaringClass();
        if (Modifier.isPublic(cls.getModifiers())) {
            return method;
        }
        final String methodName = method.getName();
        final Class<?>[] parameterTypes = method.getParameterTypes();

        // Check the implemented interfaces and subinterfaces
        method = getAccessibleMethodFromInterfaceNest(cls, methodName, parameterTypes);

        // Check the superclass chain
        if (method == null) {
            method = getAccessibleMethodFromSuperclass(cls, methodName, parameterTypes);
        }
        return method;
    }

    /**
     * <p>
     * Returns an accessible method (that is, one that can be invoked via reflection) by scanning
     * through the superclasses. If no such method can be found, return {@code null}.
     * </p>
     *
     * @param cls
     *            Class to be checked
     * @param methodName
     *            Method name of the method we wish to call
     * @param parameterTypes
     *            The parameter type signatures
     * @return the accessible method or {@code null} if not found
     */
    private static Method getAccessibleMethodFromSuperclass(final Class<?> cls, final String methodName,
            final Class<?>... parameterTypes) {
        Class<?> parentClass = cls.getSuperclass();
        while (parentClass != null) {
            if (Modifier.isPublic(parentClass.getModifiers())) {
                try {
                    return parentClass.getMethod(methodName, parameterTypes);
                } catch (final NoSuchMethodException e) {
                    return null;
                }
            }
            parentClass = parentClass.getSuperclass();
        }
        return null;
    }

    /**
     * <p>
     * Returns an accessible method (that is, one that can be invoked via reflection) that
     * implements the specified method, by scanning through all implemented interfaces and
     * subinterfaces. If no such method can be found, return {@code null}.
     * </p>
     *
     * <p>
     * There isn't any good reason why this method must be {@code private}. It is because there
     * doesn't seem any reason why other classes should call this rather than the higher level
     * methods.
     * </p>
     *
     * @param cls
     *            Parent class for the interfaces to be checked
     * @param methodName
     *            Method name of the method we wish to call
     * @param parameterTypes
     *            The parameter type signatures
     * @return the accessible method or {@code null} if not found
     */
    private static Method getAccessibleMethodFromInterfaceNest(Class<?> cls, final String methodName,
            final Class<?>... parameterTypes) {
        // Search up the superclass chain
        for (; cls != null; cls = cls.getSuperclass()) {

            // Check the implemented interfaces of the parent class
            final Class<?>[] interfaces = cls.getInterfaces();
            for (int i = 0; i < interfaces.length; i++) {
                // Is this interface public?
                if (!Modifier.isPublic(interfaces[i].getModifiers())) {
                    continue;
                }
                // Does the method exist on this interface?
                try {
                    return interfaces[i].getDeclaredMethod(methodName, parameterTypes);
                } catch (final NoSuchMethodException e) { // NOPMD
                    /*
                     * Swallow, if no method is found after the loop then this method returns null.
                     */
                }
                // Recursively check our parent interfaces
                Method method = getAccessibleMethodFromInterfaceNest(interfaces[i], methodName, parameterTypes);
                if (method != null) {
                    return method;
                }
            }
        }
        return null;
    }

    /**
     * <p>
     * Finds an accessible method that matches the given name and has compatible parameters.
     * Compatible parameters mean that every method parameter is assignable from the given
     * parameters. In other words, it finds a method with the given name that will take the
     * parameters given.
     * </p>
     *
     * <p>
     * This method is used by
     * {@link #invokeMethod(Object object, String methodName, Object[] args, Class[] parameterTypes)}.
     * </p>
     *
     * <p>
     * This method can match primitive parameter by passing in wrapper classes. For example, a
     * {@code Boolean} will match a primitive {@code boolean} parameter.
     * </p>
     *
     * @param cls
     *            find method in this class
     * @param methodName
     *            find method with this name
     * @param parameterTypes
     *            find method with most compatible parameters
     * @return The accessible method
     */
    public static Method getMatchingAccessibleMethod(final Class<?> cls, final String methodName,
            final Class<?>... parameterTypes) {
        try {
            final Method method = cls.getMethod(methodName, parameterTypes);
            MemberUtils.setAccessibleWorkaround(method);
            return method;
        } catch (final NoSuchMethodException e) { // NOPMD - Swallow the exception
        }
        // search through all methods
        Method bestMatch = null;
        final Method[] methods = cls.getMethods();
        for (final Method method : methods) {
            // compare name and parameters
            if (method.getName().equals(methodName)
                    && ClassUtils.isAssignable(parameterTypes, method.getParameterTypes(), true)) {
                // get accessible version of method
                final Method accessibleMethod = getAccessibleMethod(method);
                if (accessibleMethod != null
                        && (bestMatch == null || MemberUtils.compareParameterTypes(accessibleMethod.getParameterTypes(),
                                bestMatch.getParameterTypes(), parameterTypes) < 0)) {
                    bestMatch = accessibleMethod;
                }
            }
        }
        if (bestMatch != null) {
            MemberUtils.setAccessibleWorkaround(bestMatch);
        }
        return bestMatch;
    }

}
